Copolymer compositions particularly useful as additives for hydrocarbon oils

Abstract

New compositions, useful as viscosity additives, having dispersing properties in various hydrocarbon oils, are disclosed, which comprise: recurrent units derived from one or more acrylic or methacrylic esters (e.g. 55-99.8% by weight), recurrent units derived from one or more nitrogenous vinyl monomers obtained by reacting triallylcyanurate with aliphatic amines or polyamines (e.g. 0.2-10% by weight), and optionally recurrent units derived from one or more vinyl aromatic monomers (e.g. 0-35% by weight). These copolymer compositions generally have a weight average molecular weight from 30,000 to 800,000 and a polydispersity generally lower than 5. They can be prepared by any radical copolymerization process using for example azoic or peroxydic initiators. The copolymer compositions considered are used as additives for improving the rheological properties of hydrocarbon oils. In addition, they exhibit good dispersing properties.

What is claimed as the invention is: 
     
       1. A copolymer composition, comprising (a) recurrent units derived from at least one acrylic or methacrylic ester; (b) recurrent units derived from at least one nitrogeneous vinyl monomer obtained by reacting triallylcyanurate with at least one monoprimary aliphatic amine complying with the general formula:   R.sup.1 --NH--A).sub.x NH.sub.2     wherein R 1  is at least one ethylenically unsaturated monovalent aliphatic radical, x ranges from 1 to 10 or may be a zero when R 1  contains at least 4 carbon atoms and A is an alkylene group of 2-6 carbon atoms, said at least one monoprimary aliphatic amine being used in a proportion of 1 to 2 moles per mole of triallylcyanurate; and optionally (c) recurrent units derived from at least one vinyl aromatic monomer.   
     
     
       2. A copolymer composition according to claim 1, wherein said vinylaromatic monomer is styrene. 
     
     
       3. A copolymer composition according to claim 1, wherein said acrylic or methacrylic ester consists of at least one linear or branched alkyl acrylate having 1 to 22 carbon atoms in the alkyl group. 
     
     
       4. A copolymer compositor according to claim 1, wherein said at least one nitrogeneous vinyl monomer in part comprises at least one compound obtained by reacting triallylcyanurate with at least one monoprimary aliphatic amine complying with the general formula:   R.sup.1 --NH--A).sub.x NH.sub.2     wherein R 1  is at least one alkyl radical of 8-24 carbon atoms, x ranges from 0 to 10 and A, defined when x is not zero, is an alkylene group of 2-6 carbon atoms.   
     
     
       5. A copolymer composition according to claim 1, wherein said acrylic or methacrylic ester is used in a proportion from 55 to 99.8% by weight, said nitrogenous vinyl monomer is used in a proportion 0.2 to 10% by weight, and said vinylaromatic monomer is used in a proportion of not more than 35% by weight, with respect to the total weight of said monomers. 
     
     
       6. A copolymer composition according to claim 1, wherein said monomer (b) is present in a concentration of 0.5-4% by weight and said vinyl aromatic monomer is styrene in a proportion of above 0% by weight. 
     
     
       7. A copolymer composition according to claim 1, having a weight average molecular weight from about 30,000 to 800,000 and a polydispersity lower than 5. 
     
     
       8. A copolymer composition according to claim 1, having a weight average molecular weight from about 200,000-400,000 and a polydispersity of 2.7-4.7. 
     
     
       9. A copolymer composition according to claim 1, wherein said nitrogenous vinyl monomer results from the reaction of said monoprimary aliphatic amine with triallylcyanurate with removal of the allyl alcohol formed. 
     
     
       10. A copolymer composition according to claim 1 wherein said nitrogenous vinyl monomer is at least one obtained with a monoprimary aliphatic amine of formulae   R.sup.1 --NH--CH.sub.2 --.sub.3 NH.sub.2       R.sup.1 --NH--CH.sub.2).sub.3 ].sub.2 NH.sub.2       R.sup.1 --NH--CH.sub.2).sub.3 ].sub.3 NH.sub.2     wherein R 1  is an ethylenically unsaturated monovalent aliphatic radical.   
     
     
       11. A copolymer composition according to claim 10 wherein, in the formulae, R 1  is oleyl. 
     
     
       12. A copolymer composition comprising: (a) 55 to 99.8% by weight of least one linear or branched alkyl acrylate or methylacrylate having 1-22 carbon atoms in the alkyl group;   (b) 0.2-10% by weight of at least one nitrogenous vinyl monomer of formula ##STR9##  wherein R 1  is at least one ethylenically unsaturated monovalent aliphatic radical of 1-24 carbon atoms radical, x ranges from 1 to 10 or is zero when R 1  contains at least 4 carbon atoms and A, defined when x is not zero, is an alkylene group of 2-6 carbon atoms; and   (c) 0-35% by weight of a vinyl aromatic monomer.   
     
     
       13. A polymer composition according to claim 12, wherein in the formulae x is 1, 2 or 3, A is --CH 2  -- 3  and R 1  is oleyl. 
     
     
       14. A copolymer composition according to claim 12 wherein said at least one nitrogenous vinyl monomer in part comprises at least one compound of formula (I) or (II) wherein R 1  is at least one alkyl radical of 8-24 carbon atoms, x ranges from 0 to 10, and A, defined when x is not zero, is an alkylene group of 2-6 carbon atoms.